This should perhaps go into the bug tracker, but I couldn't find a media
capture TF component.
The spec currently says:
---
kind of type DOMString, readonly
The MediaStreamTrack.kind attribute must return the string "audio" if
the objectÃ­s corresponding track is or was an audio track, "video" if
the corresponding track is or was a video track, and a user agent
defined string otherwise.
---
I believe the last part about user agent defined strings is a leftover
from the time where we had a combined list for all track types. Since
we're aligned with the media elements and have a separate track list for
each kind of track I think we should remove the part about user agent
defined track kinds. Any future track kinds we add should get similar
status as "audio" and "video" and get its own track list.
/Adam